<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>bootcss2</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="static/css/bootstrap.min.css">
</head>
<body>
<div class="container">
    <div class="row">
        <div class="col-lg-3 col-md-4 col-sm-6 bg-danger">aaaaaaa</div>
        <div class="col-lg-3 col-md-4 col-sm-6 bg-info">aaaaaaa</div>
        <div class="col-lg-3 col-md-4 col-sm-6 bg-primary">aaaaaaa</div>
        <div class="col-lg-3 col-md-4 col-sm-6 bg-success">aaaaaaa</div>
        <div class="col-lg-3 col-md-4 col-sm-6 bg-warning">aaaaaaa</div>
        <div class="col-lg-3 col-md-4 col-sm-6 bg-primary">aaaaaaa</div>
        <div class="col-lg-3 col-md-4 col-sm-6 bg-danger">aaaaaaa</div>
        <div class="col-lg-3 col-md-4 col-sm-6 bg-success">aaaaaaa</div>
    </div>
</div>
</body>
</html>